Chained flashlight system

ABSTRACT

A chained flashlight system includes multiple flashlights; multiple lighting control devices that control lighting of the flashlights, respectively; a communication wire; and a traffic control device. The lighting control devices include receiving units, controlling units, and power supply units, respectively and are coupled to the traffic control device by the same communication wire. The traffic control device simultaneously sends a lighting signal to the lighting control devices via the communication wire. The receiving units of the lighting control devices receive the lighting signal. The controlling units of the lighting control devices turn ON the power supply units, respectively, on the basis of the time condition from reception of the lighting signal to turning ON of the power supply units, set for the respective flashlights. The flashlights are lit by turning ON the respective power supply units of the lighting control devices.

TECHNICAL FIELD

The present invention relates to a chained flashlight system.

BACKGROUND ART

In the existing chained flashlight systems used in Japanese airports,for example, 29 flashlights (hereinafter also referred to as “lamps”)are repeatedly lit sequentially from one end of a runway to the otherend for about 17 milliseconds per one lamp (0.5 seconds per one cycle),and a lighting signal is directly sent from the traffic controlapparatus (traffic control device) to each lamp. Therefore, manycommunication wires are used between the apparatus and each lamp.

As a method of reducing the number of communication wires, for example,it is conceivable to use an optical fiber, but it is difficult to newlyintroduce an expensive optical fiber into an airport, and the opticalfiber cannot be easily attached to and detached from a flashlightrequiring high waterproofness, has poor ease of handling, and involves ahigh maintenance cost (Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: JP H10-181695 A

SUMMARY OF INVENTION Technical Problem

Hence, it is an object of the present invention to provide a chainedflashlight system which can reduce the number of existing communicationwires while using some of the communication wires.

Solution to Problem

In order to achieve the aforementioned object, according to the presentinvention, there is provided a chained flashlight system which includes:multiple flashlights; multiple lighting control devices that controllighting of the respective flashlights, a communication wire; and atraffic control device. In the chained flashlight system, each lightingcontrol device comprises: a receiving unit, a controlling unit, and apower supply unit. The lighting control devices are coupled to thetraffic control device by the same communication wire. The trafficcontrol device simultaneously sends a lighting signal to the lightingcontrol devices via the communication wire. The receiving unit of eachlighting control device receives the lighting signal. The controllingunit of each lighting control device turns ON the corresponding powersupply unit on the basis of a time condition from reception of thelighting signal to turning ON of the power supply device, set for thecorresponding flashlight. Each flashlight is lit by turning ON thecorresponding power supply unit of each lighting control device.

Advantageous Effects of Invention

The present invention can provide a chained flashlight system which canreduce the number of existing communication wires while using some ofthe communication wires.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example configuration of thechained flashlight system according to the first embodiment.

FIG. 2 is a block diagram illustrating an example configuration of thechained flashlight system according to the second embodiment.

DESCRIPTION OF EMBODIMENTS

The chained flashlight system of the present invention is configuredsuch that, for example, the communication wire is a bidirectionallycommunicable communication wire that can send a lighting signal from thetraffic control device to the lighting control devices and can feedinformation back from the lighting control devices to the trafficcontrol device, and the lighting control devices are coupled to thetraffic control device by the communication wire.

The chained flashlight system of the present invention is configuredsuch that, for example, it further includes a power supply device and apower supply wire, and the lighting control devices are coupled to thepower supply device by the same power supply wire. The power supply wireis of preferably a single-phase two-wire type.

The chained flashlight system of the present invention is configuredsuch that, for example, flashlights are LED flashlights.

The chained flashlight system of the present invention is configuredsuch that, for example, the traffic control device furthersimultaneously sends a luminous intensity designation signal to thelighting control devices via the communication wire, the receiving unitof each lighting control device receives the luminous intensitydesignation signal, the controlling unit of each lighting control deviceturns ON the corresponding power supply unit such that luminousintensity of the corresponding flashlight during an ON-state of thepower supply unit becomes luminous intensity designated by the luminousintensity designation signal, and each flashlight is lit so as to haveluminous intensity designated by the luminous intensity designationsignal by turning ON the corresponding power supply unit of eachlighting control device.

The chained flashlight system of the present invention is configuredsuch that, for example, each lighting control device further includes anabnormality sensing unit, the abnormality sensing unit of each lightingcontrol device detects an abnormality of at least one unit selected fromthe group consisting of the corresponding flashlight, the correspondingreceiving unit, the corresponding controlling unit, and thecorresponding power supply unit and sends an abnormal signal to thetraffic control device via the communication wire.

The chained flashlight system of the present invention is configuredsuch that, for example, each flashlight further includes a heater; thechained flashlight system further includes heater control devices thatcontrol heating of the respective flashlights, each heater controldevice includes: a heater receiving unit, a heater controlling unit, anda heater power supply unit, the lighting control devices are coupled tothe traffic control device by the same communication wire, the trafficcontrol device simultaneously sends a heating signal to the heatercontrol devices via the communication wire, the heater receiving unit ofeach heater control device receives the heating signal, the heatercontrolling unit of each heater control device turns ON thecorresponding heater power supply unit, and the heater of eachflashlight is lit by turning ON the corresponding heater power supplyunit of each heater control device.

The chained flashlight system of the present invention is configuredsuch that, for example, the traffic control device sends 1-bitinformation in the lighting signal for a predetermined pulse signalwidth. The predetermined pulse signal width is preferably 0.1 to 499.9milliseconds.

The following describes the chained flashlight system of the presentinvention in details with reference to the drawings. However, thepresent invention is not limited to the following description. Note herethat there may be cases where the same reference numerals are given tothe same components in FIGS. 1 and 2 below, and descriptions thereof areomitted. Furthermore, in the drawings, for ease of description,illustration of the structures of the components may be simplified asappropriate, and the ratio of sizes of components and the like may beschematically indicated contrary to reality.

FIRST EMBODIMENT

FIG. 1 is a block diagram illustrating an example configuration of thechained flashlight system (hereinafter also referred to as “system”)according to the present embodiment. As shown in FIG. 1, a system 10according to the present embodiment includes flashlights A₁ to A_(n),lighting control devices B₁ to B_(n), a communication wire C, and atraffic control device D. The lighting control devices B₁ to B_(n)include receiving units b1 ₁ to b1 _(n), controlling units b2 ₁ to b2_(n), and power supply units b3 ₁ to b3 _(n), respectively. In thesystem 10 according to the present embodiment, the flashlights A₁ toA_(n) are coupled (hereinafter also referred to as “connected”) to thelighting control devices B₁ to B_(n), respectively. The lighting controldevices B₁ to B_(n) are connected to the traffic control device D by thesame communication wire C. Although not shown, in the system 10according to the present embodiment, in order to guide an aircraft to arunway, the flashlights A₁ to A_(n) are arranged linearly such that theflashlight A₁ is arranged at an end on the side opposite to an approachdirection for the aircraft relative to an end at an approach entrancefor the aircraft in the runway, and the flashlight A_(n) is arranged atthe end on the approach entrance side of the runway. In FIG. 1, an arrowAD indicates an approach direction for the aircraft.

The flashlights A₁ to A_(n) may be any lamp capable of emitting flashes,and known flashlights can be used. Specific examples thereof include asxenon light (xenon flashlight), an LED light (LED flashlight), and thelike, and the LED light is preferable because it can reduce powerconsumption. The number n of sets based on one set of a flashlight and alighting control device corresponding to the flashlight in the system 10according to the present embodiment is an integer of three or more.However, the number n of the sets may be an integer of two or more andcan be set, as appropriate, according to the number of sets offlashlights in the chained flashlights, defined in each country, forexample. Specifically, the number n of the sets is, for example, 2 to30, and is, for example, 29 in Japan. Moreover, in each set, the numberof flashlights A_(n) connected to the lighting control device B_(n) isnot particularly limited and is, for example, one. The flashlights A₁ toA_(n) may have address information Ia_(n) which can identify theflashlights A₁ to A_(n), for example.

The lighting control devices B₁ to B_(n) control lighting of theflashlights A₁ to A_(n), respectively. In the system 10 according to thepresent embodiment, the lighting control devices B₁ to B_(n) have thereceiving units b1 ₁ to b1 _(n), the controlling units b2 ₁ to b2 _(n),and the power supply units b3 ₁ to b3 _(n), respectively and may furtherinclude other units, specifically the respective abnormality sensingunits to be described below. The lighting control devices B₁ to B_(n)may have address information Ib_(n) which can identify the lightingcontrol devices B₁ to B_(n), for example.

The receiving units b1 ₁ to b1 _(n) receive a lighting signal. As eachof the receiving units b1 ₁ to b1 _(n), a receiver capable of receivingan analog signal or a digital signal according to the type of the signalsent by the traffic control device D can be used, and specific examplesof the receiver include an analog signal receiver and a digital signalreceiver. When the receiving units b1 ₁ to b1 _(n) are analog signalreceivers, they preferably include the respective digital-to-analogconverters. The receiving units b1 ₁ to b1 _(n) may further have asending function of being capable of sending information and the like onthe lighting control devices B₁ to B_(n). In this case, the receivingunits b1 ₁ to b1 _(n) can also be referred to as, for example,sending/receiving units. The information can be, for example, anabnormal signal to be described below. When the receiving units b1 ₁ tob1 _(n) have a sending function and send the information to the trafficcontrol device D by the analog signal, they preferably include therespective digital-to-analog converters. The lighting signal is, forexample, a signal for instructing the flashlights A₁ to A_(n) to emitflashes. If the flashlights A₁ to A_(n) are lamps, such as LED lights orthe like, that continue to be lit once they are lit, the lighting signalpreferably includes at least one of a signal relating to the lightingtime of the flashlights A₁ to A_(n) or an extinguishing signal forturning OFF the flashlights A₁ to A_(n) after the elapse of the lightingtime. The lighting time is, for example, 0.01 to 50 milliseconds.

The controlling units b2 ₁ to b2 _(n) turn ON the power supply units b3₁ to b3 _(n), respectively, on the basis of the time condition from thereception of the lighting signal to the turning ON of the power supplyunits b3 ₁ to b3 _(n), set for the respective flashlights A₁ to A_(n).The controlling units b2 ₁ to b2 _(n) may be any devices capable ofturning ON the power supply units b3 ₁ to b3 _(n), respectively, andexamples thereof include a CPU (Central Processing Unit), amicroprocessor, and a microcontroller. The time condition may be a timecondition where the flashlights A₁ to A_(n) are lit sequentially at apredetermined time interval T_(p) in order from the flashlight A₁ to theflashlight A_(n). As a specific example, the time condition for thecontrolling unit b2 _(n) is a time condition where the power supply unitb3 _(n) is turned ON after the elapse of T_(p)×n seconds from thereception of the lighting signal. The predetermined time interval T_(p)is, for example, about 17 milliseconds. The predetermined time intervalT_(p) may be set considering a time lag T occurring until the lightingcontrol devices B₁ to B_(n) receive the lighting signal sentsimultaneously, for example. If the flashlights A₁ to A_(n) are LEDlights, and the lighting signal includes at least one of a signalrelating to the lighting time of the flashlights A₁ to A_(n) or anextinguishing signal for turning OFF the flashlights A₁ to A_(n) afterthe elapse of the lighting time, the controlling units b2 ₁ to b2 _(n)preferably turn OFF the power supply units b3 ₁ to b3 _(n) on the basisof the signal relating to the lighting time or the extinguishing signal.

The flashlights A₁ to A_(n) are lit by turning ON the power supply unitsb3 ₁ to b3 _(n). The power supply units b3 ₁ to b3 _(n) may be any meanscapable of lighting the respective flashlights A₁ to A_(n), and knownvoltage-applying means may be used, for example. When the flashlights A₁to A_(n) are xenon lights, the power supply units b3 ₁ to b3 _(n)preferably further send a trigger signal for causing the flashlights A₁to A_(n) to emit light. The power supply units b3 ₁ to b3 _(n) mayfurther include the respective known electric accumulation means such ascondensers (capacitors), for example. When the power supply units b3 ₁to b3 _(n) include the respective electric accumulation means, the powersupply units b3 ₁ to b3 _(n) turn ON the respective flashlights A₁ toA_(n) by supplying electric power in the electric accumulation means tothe respective flashlights A₁ to A_(n), for example.

The communication wire C may be any communication wire capable ofperforming data communication, and a known communication wire can beused. Specific examples of the communication wire C include a metalcommunication cable and an optical fiber communication cable. Thecommunication wire C is preferably a metal communication cable becauseit is easy to attach and detach. In the system 10 according to thepresent embodiment, the communication wire C is connected to thelighting control devices B₁ to B_(n) in bus topology because it is easyto use the existing communication wire C, for example. However, thecommunication wire C may be connected to the lighting control devices B₁to B_(n), for example, in series as long as each of the lighting controldevices B₁ to B_(n) and the traffic control device C are connected toeach other by the same communication wire C, i.e., a commoncommunication wire C. In the system 10 according to the presentembodiment, the communication wire C functions as a communication wirefor sending a lighting signal from the traffic control device D to thelighting control devices B₁ to B_(n). Therefore, the communication wireC can also be referred to as an input communication wire, for example.The number of communication wires C is not particularly limited and maybe, for example, one or two or more. In the latter case, one of the twoor more communication wires may be used as an input communication wire,and the other one may be used as an output communication wire forfeeding information back from the lighting control devices B₁ to B_(n)to the traffic control device D. In this case, for example, onecommunication wire C may serve as both of the input communication wireand the output communication wire. In this case, the communication wireC may be, for example, a bidirectionally communicable communicationwire.

The traffic control device D simultaneously sends a lighting signal tothe lighting control devices B₁ to B_(n) via the communication wire C.The traffic control device D may be a device capable of generating thelighting signal and can be, for example, a CPU, a microprocessor, or amicrocontroller.

Next, a method for lighting the flashlights A₁ to A_(n) using the system10 according to the present embodiment will be described.

First, the traffic control device D simultaneously sends a lightingsignal to the lighting control devices B₁ to B_(n) via the communicationwire C. The number of times of sending the lighting signal from thetraffic control device D may be one or multiple times, and however, thelatter is preferable. In the latter case, it is preferable that thetraffic control device D repeatedly sends the lighting signal for a timeperiod designated by a user, such as an air traffic controller, at apredetermined time interval T_(f), for example. The predetermined timeinterval T_(f) is, for example, about 500 milliseconds.

Next, the receiving units b1 ₁ to b1 _(n) of the lighting controldevices B₁ to B_(n) receive the lighting signal sent by the trafficcontrol device D. When the receiving units b1 ₁ to b1 _(n) receive thelighting signal, the controlling units b2 ₁ to b2 _(n) turn ON the powersupply units b3 ₁ to b3 _(n), respectively, on the basis of the timecondition from the reception of the lighting signal to the turning ON ofthe power supply units b3 ₁ to b3 _(n), set for the respectiveflashlights A₁ to A_(n). The flashlights A₁ to A_(n) are lit by turningON the respective power supply units b3 ₁ to b3 _(n). As a specificexample, the time condition for the controlling unit b2 _(n) is a timecondition where the power supply unit b3 _(n) is turned ON after theelapse of T_(p)×n seconds from the reception of the lighting signal.When the predetermined time interval T_(p) is about 17 milliseconds, theflashlights A₁, A₂, [. . . ], A_(n) are lit after about 17 milliseconds,about 34 milliseconds, [. . . ], about 17×n milliseconds from thereception of the lighting signal, respectively. The flashlights A₁ toA_(n) are arranged linearly such that the flashlight A₁ is arranged atan end on the side opposite to an approach direction for the aircraftrelative to an end at an approach entrance for the aircraft in therunway, and the flashlight A_(n) is arranged at the end on the approachentrance side of the runway. Therefore, in the case where a pilot of theaircraft sees the flashlights A₁ to A_(n), the flashlights A₁ to A_(n)are lit sequentially at a time interval of about 17 milliseconds alongan approach direction for the aircraft (an direction indicated by thearrow AD).

As described above, in the system 10 according to the presentembodiment, flashlights A₁ to A_(n) are lit after the reception of thelighting signal sent by the traffic control device D on the basis of thetime condition for the controlling units b2 ₁ to b2 _(n) of the lightingcontrol devices B₁ to B_(n). In the existing chained flashlight system,a communication wire is provided for each lighting control device toindividually send a lighting signal to each lighting control device bythe traffic control device. However, the system 10 according to thepresent embodiment is not required to provide a communication wire foreach lighting control device, and a communication wire thus can beprovided at low cost. In addition, the system 10 according to thepresent embodiment can reduce the number of existing communication wiresto, for example, one while using the existing communication wire, byconnecting one of the existing communication wires to all the lightingcontrol devices B₁ to B_(n), for example.

The system 10 according to the present embodiment may include, forexample, a pair of communication wires. In this case, in the system 10according to the present embodiment, the communication wires arebidirectionally communicable wires that can send a lighting signal fromthe traffic control device to the lighting control devices and can feedinformation back from the lighting control devices to the trafficcontrol device, and the lighting control devices are preferably coupledto the traffic control device. The lighting control devices arepreferably coupled to the traffic control device by the samecommunication wire, for example. The communication wire may be, forexample, a pair of communication wires. In this case, the system 10according to the present embodiment includes a pair of communicationwires, one of the communication wires is an input communication wire forsending a lighting signal from the traffic control device to thelighting control devices, and the other communication wire is an outputcommunication wire for feeding information back from the lightingcontrol devices to the traffic control device, and the lighting controldevices are preferably coupled to the traffic control device by the sameoutput communication wire. Between the pair of communication wires, onecan also be referred to as a (+) wire, and the other can also bereferred a (−) wire, for example. The input communication wire and theoutput communication wire can be described with reference to thedescription of the above-mentioned communication wire, for example. Withthe bidirectionally communicable communication wire or the outputcommunication wire, information of an abnormal signal to be describedbelow can be fed back to the traffic control device, for example.Accordingly, for example, statuses of the flashlights A₁ to A_(n) andthe lighting control devices B₁ to B_(n) can be monitored, and they canbe maintained at an appropriate time.

The system 10 according to the present embodiment further includes, forexample, a power supply device and a power supply wire, and the lightingcontrol devices are coupled to the power supply device by the same powersupply wire. The power supply device may supply electric power to theflashlights and the lighting control devices via the power supply wire,and a known power supply can be used, for example. The power supply wireis not particularly limited, and a known electric wire can be used. Thetype of the power supply wire is not particularly limited, and can bedetermined, as appropriate, according to a power distribution system.The type can be, for example, a single-phase two-wire type, asingle-phase three-wire type, or a three-phase three-wire type and ispreferably a single-phase two-wire type because wiring is easy, andinstallation can be performed inexpensively.

The system 10 according to the present embodiment is preferablyconfigured such that, for example, the traffic control device Dsimultaneously sends a luminous intensity designation signal to thelighting control devices B₁ to B_(n) via the communication wire C, thereceiving units b1 ₁ to b1 _(n) of the lighting control devices B₁ toB_(n) receive the luminous intensity designation signal, the controllingunits b2 ₁ to b2 _(n) of the lighting control devices B₁ to B_(n) turnsON the respective power supply units b3 ₁ to b3 _(n) such that luminousintensity of the flashlights A₁ to A_(n) during an ON-state of therespective power supply units b3 ₁ to b3 _(n) becomes luminous intensitydesignated by the luminous intensity designation signal, and theflashlights A₁ to A_(n) are lit so as to have luminous intensitydesignated by the luminous intensity designation signal by turning ONthe power supply units b3 ₁ to b3 _(n) of the lighting control devicesB₁ to B_(n), respectively. The luminous intensity of the flashlights A₁to A_(n) during the ON state, designated by the luminous intensitydesignation signal, is, for example, a peak luminous intensity of theflashlights A₁ to A_(n) after turning ON of the power supply units b3 ₁to b3 _(n). The luminous intensity designation signal may be, forexample, a signal designating a numerical value of a specific luminousintensity or a signal designating a luminous intensity set in advance.The luminous intensity set in advance is not particularly limited andcan be, for example, high lighting (e.g., 6000 to 20000 cd), mediumlighting (e.g., 600 to 2000 cd), or low lighting (e.g., 100 to 450 cd).As described above, in the case where the luminous intensity designationsignal is a signal designating a luminous intensity set in advance, forexample, the luminous intensity may be set such that when the trafficcontrol device D sends the lighting signal, the flashlights A₁ to A_(n)emit flashes with a luminous intensity of high lighting, and when thetraffic control device D sends the luminous intensity designationsignal, the flashlights A₁ to A_(n) emit flashes with a luminousintensity of medium lighting or low lighting. The system 10 according tothe present embodiment can adjust the luminous intensity of theflashlights A₁ to A_(n) to be appropriate depending on the differentcircumstances of the ambient brightness. such as, for example, in themorning, day, evening, night, etc., by allowing the traffic controldevice D to send the luminous intensity designation signal. The pilot ofthe aircraft thus can more clearly recognize the flashes of theflashlights A₁ to A_(n).

In the system 10 according to the present embodiment, the lightingcontrol devices B₁ to B_(n) preferably further include the respectiveabnormality sensing units, for example. In this case, it is preferredthat the abnormality sensing units of the lighting control devices B₁ toB_(n) detect an abnormality of at least one unit selected from the groupconsisting of the flashlights A₁ to A_(n), the receiving units b1 ₁ tob1 _(n), the controlling units b2 ₁ to b2 _(n), and the power supplyunits b3 ₁ to b3 _(n) and send an abnormal signal to the traffic controldevice D via the communication wire. In the case where the communicationwire is a pair of communication wires, the abnormality sensing unitspreferably send an abnormal signal to the traffic control device D viathe output communication wire, for example. The abnormality sensingunits can be determined, as appropriate, according to, for example, thetype of the flashlights A₁ to A_(n), the receiving units b1 ₁ to b1_(n), the controlling units b2 ₁ to b2 _(n), and the power supply unitsb3 ₁ to b3 _(n) and can be means for sensing voltages, currents, and thelike of the respective units. Since the abnormality sensing units caneasily identify a flashlight and a unit with abnormality, the addressinformation Ia_(n) of the flashlights A₁ to A_(n) or the addressinformation Ib_(n) of the lighting control devices B₁ to B_(n) may alsobe sent to the abnormality sensing units, for example. Abnormalities ofthe flashlights A₁ to A_(n) and each unit may be, for example,abnormalities of the flashlights A₁ to A_(n) and each unit themselves orabnormalities such as breakage of wire in the connection of theflashlights A₁ to A_(n) and each unit to other units. In the case wherethe number of communication wires C is one, the abnormality sensingunits may send an abnormal signal via one communication wire C as asubstitute for the output communication wire, for example. With theabnormality sensing units, the abnormal signal can be fed back to thetraffic control device. Accordingly, for example, abnormalities of theflashlights A₁ to A_(n) and the lighting control devices B₁ to B_(n) canbe monitored, and they can be maintained at an appropriate time.

In the system 10 according to the present embodiment, the flashlights A₁to A_(n) preferably further include the respective heaters, for example.Each heater is not particularly limited, and a known heater can be used.In the case where the flashlights A₁ to A_(n) in the system 10 accordingto the present embodiment include the respective heaters, it ispreferable that the system 10 according to the present embodimentincludes heater control devices that correspond to the respectiveflashlights A₁ to A_(n) and controls the heaters of the respectiveflashlights A₁ to A_(n), and each heater control device includes aheater receiving unit, a heater controlling unit, and a heater powersupply unit, the heater control devices are coupled to the trafficcontrol device D by the same communication wire, the traffic controldevice D simultaneously sends a heating signal to the heater controldevices via the communication wire, the heater receiving unit of eachheater control device receives the heating signal, the heatercontrolling unit of each heater control device turns ON thecorresponding heater power supply unit, and the heaters of theflashlights A₁ to A_(n) are lit by turning ON the respective heaterpower supply units of the heater control devices. Specific examples ofthe heater receiving unit, the heater controlling unit, and the heaterpower supply unit can be described with reference to the description ofthe specific examples of the receiving units b1 ₁ to b1 _(n), thecontrolling units b2 ₁ to b2 _(n), and the power supply units b3 ₁ to b3_(n), for example. Any one or two or more units among the receivingunits b1 ₁ to b1 _(n), the controlling units b2 ₁ to b2 _(n), and thepower supply units b3 ₁ to b3 _(n) may also have a function of theheater receiving unit, the heater controlling unit, and the heater powersupply unit, for example. The communication wire C may also serve as acommunication wire for sending the heating signal. When the flashlightsA₁ to A_(n) include the respective heaters, snow and ice on theflashlights A₁ to A_(n) can be melted in cold climate areas where snowfalls or freeze occurs, for example. Therefore, for example, a reductionin luminous intensity of the flashlights A₁ to A_(n) can be prevented,and the pilot of the aircraft can more clearly recognize the flashes ofthe flashlights A₁ to A_(n).

In the system 10 according to the present embodiment, the trafficcontrol device D sends 1-bit information in the lighting signal for apredetermined pulse signal width, for example. The predetermined pulsesignal width is, for example, 0.1 to 499.9 milliseconds. As a specificexample, the lighting signal is 256-bit information, and when thelighting signal is sent as one or more signals, the traffic controldevice D sends 1-bit information for the first time and thereafter sendsthe remaining 255-bit information by 1 bit at a predetermined timeinterval, for example. The predetermined time interval is, for example,2.3 to 1.95 milliseconds. The predetermined time interval is, forexample, the time required to send (n+1)th 1-bit information in thelighting signal from the time at which n-th 1-bit information of thelighting signal is sent. The predetermined time interval is preferablyconstant. The proportion of the signal width (pulse width) during which1-bit information is sent at each interval is not particularly limited.The proportion is, for example, 50% to 90%. When the system 10 accordingto the present embodiment can designate the luminous intensity, thetraffic control device D may send 1-bit information in the luminousintensity designation signal for a predetermined pulse signal width inaddition to or as a substitute for the lighting signal. The system 10according to the present embodiment includes the heaters, the trafficcontrol device D may send 1-bit information in the heating signal for apredetermined pulse signal width in addition to or as a substitute forthe lighting signal. When the system 10 according to the presentembodiment includes the abnormality sensing units, the traffic controldevice D may receive 1-bit information in the abnormal signal sent bythe abnormality sensing units for a predetermined pulse signal width. Inthis case, the abnormality sensing units may send 1-bit information inthe abnormal signal for a predetermined pulse signal width. Thepredetermined pulse signal widths for the luminous intensity designationsignal, the heating signal, and the abnormal signal can be describedwith reference to the descriptions of the predetermined pulse signalwidth for the lighting signal by reading the “lighting signal” as the“luminous intensity designation signal”, the “heating signal”, or the“abnormal signal”, for example. As described above, when the trafficcontrol device D sends or receives 1-bit information in each signal fora predetermined pulse signal width, an influence of noise that may becontained in each signal by surge or the like can be reduced, forexample. Therefore, the system 10 including the traffic control device Dthat sends or receives 1-bit information in each signal for apredetermined pulse signal width is excellent in resistance to noise andsignal deterioration, for example. Accordingly, as a communication wireC, a communication wire that is not an optical fiber communication cableor a communication wire that does not include a shielding wire, i.e., anexisting communication wire can be used. Furthermore, by setting theproportion of the signal width to the above-mentioned proportion, theresistance to noise can further be improved, and deterioration of eachsignal can further be prevented, for example.

SECOND EMBODIMENT

The second embodiment is an another example of the chained flashlightsystem including a pair of communication wires and the abnormalitysensing units. FIG. 2 shows an example configuration of a chainedflashlight system 20 according to the present embodiment.

As shown in FIG. 2, the system 20 according to the present embodiment isconfigured such that the system 10 according to the first embodimentincludes a pair of communication wires C as a substitute for thecommunication wire C, and the pair of communication wires C includes aninput communication wire C1 and an output communication wire C2, and thelighting control devices B₁ to B_(n) include abnormality sensing unitsb4 ₁ to b4 _(n), respectively. The lighting control devices B₁ to B_(n)are connected to the traffic control device D by the same inputcommunication wire C1 and the same output communication wire C2. Exceptfor this, the system 20 according to the present embodiment has the sameconfiguration as the system 10 according to the first embodiment and canbe described with reference to the description of the system 10according to the first embodiment. In the system 20 according to thepresent embodiment, the abnormality sensing units b4 ₁ to b4 _(n) maydetect, for example, an abnormality of at least one unit selected fromthe group consisting of flashlights A₁ to A_(n), the receiving units b1₁ to b1 _(n), the controlling units b2 ₁ to b2 _(n), and the powersupply units b3 ₁ to b3 _(n) in the state before sending the lightingsignal. As described above, by sensing an abnormality in the statebefore sending the lighting signal, flashlights A₁ to A_(n) and thelighting control devices B₁ to B_(n) can be replaced before using theflashlights A₁ to A_(n), for example. Accordingly, the system 20according to the present embodiment can improve maintenability.

In the system 20 according to the present embodiment, the communicationwires C includes the input communication wire Cl and the outputcommunication wire C2. However, in the system 20 according to thepresent embodiment, the number of communication wires C may be one. Inthis case, the communication wire C may be, for example, abidirectionally communicable communication wire.

The present invention has been described so far with reference to theembodiments but the present invention is not limited to the foregoingembodiments. Various modifications on the configuration and details ofthe present invention that are understandable by a person skilled in theart are possible within a scope of the present invention.

The present application is based upon and claims the benefit of priorityfrom Japanese patent application No. 2017-012997, filed on Jan. 27,2017, and the entire disclosure of which is incorporated herein itsentirety by reference.

INDUSTRIAL APPLICABILITY

The present invention can provide a chained flashlight system which canreduce the number of existing communication wires while using some ofthe communication wires. Thus, the present invention is really useful inthe aeronautical field, for example.

REFERENCE SIGNS LIST

-   10, 20: chained flashlight system-   A₁, A₂, A_(n): flashlight-   AD: approach direction-   B₁, B₂, and B_(n): lighting control device-   b1 ₁, b1 ₂, b1 _(n): receiving unit-   b2 ₁, b2 ₂, b2 _(n): controlling unit-   b3 ₁, b3 ₂, b3 _(n): power supply unit-   b4 ₁, b4 ₂, and b4 _(n) abnormality sensing unit-   C: communication wire-   C1: input communication wire-   C2: output communication wire-   D: traffic control device

1-10. (canceled)
 11. A chained flashlight system, comprising: multipleflashlights; multiple lighting control devices that control lighting ofthe respective flashlights, a communication wire; and a traffic controldevice, wherein each lighting control device comprises a receiving unit,a controlling unit, and a power supply unit, the lighting controldevices are coupled to the traffic control device by the samecommunication wire, the traffic control device simultaneously sends alighting signal to the lighting control devices via the communicationwire, the receiving unit of each lighting control device receives thelighting signal, the controlling unit of each lighting control deviceturns ON the corresponding power supply unit on the basis of a timecondition from reception of the lighting signal to turning ON of thepower supply device, set for the corresponding flashlight, and eachflashlight is lit by turning ON the corresponding power supply unit ofeach lighting control device.
 12. The chained flashlight systemaccording to claim 11, wherein the communication wire is abidirectionally communicable communication wire that can send a lightingsignal from the traffic control device to the lighting control devicesand can feed information back from the lighting control devices to thetraffic control device, and the lighting control devices are coupled tothe traffic control device by the communication wire.
 13. The chainedflashlight system according to claim 12, wherein each lighting controldevice further comprises an abnormality sensing unit, the abnormalitysensing unit of each lighting control device detects an abnormality ofat least one unit selected from the group consisting of thecorresponding flashlight, the corresponding receiving unit, thecorresponding controlling unit, and the corresponding power supply unitand sends an abnormal signal to the traffic control device via thecommunication wire.
 14. The chained flashlight system according to claim12, further comprising: a power supply device and a power supply wire,wherein the lighting control devices are coupled to the power supplydevice by the same power supply wire.
 15. The chained flashlight systemaccording to claim 14, wherein the power supply wire is of asingle-phase two-wire type.
 16. The chained flashlight system accordingto claim 11, further comprising: a power supply device and a powersupply wire, wherein the lighting control devices are coupled to thepower supply device by the same power supply wire.
 17. The chainedflashlight system according to claim 16, wherein the power supply wireis of a single-phase two-wire type.
 18. The chained flashlight systemaccording to claim 11, wherein the flashlights are LED flashlights. 19.The chained flashlight system according to claim 11, wherein the trafficcontrol device further simultaneously sends a luminous intensitydesignation signal to the lighting control devices via the communicationwire, the receiving unit of each lighting control device receives theluminous intensity designation signal, the controlling unit of eachlighting control device turns ON the corresponding power supply unitsuch that luminous intensity of the corresponding flashlight during anON-state of the power supply unit becomes luminous intensity designatedby the luminous intensity designation signal, and each flashlight is litso as to have luminous intensity designated by the luminous intensitydesignation signal by turning ON the corresponding power supply unit ofeach lighting control device.
 20. The chained flashlight systemaccording to claim 11, wherein each flashlight further comprises aheater; the chained flashlight system further comprises heater controldevices that control heating of the respective flashlights, each heatercontrol device comprises a heater receiving unit, a heater controllingunit, and a heater power supply unit, the lighting control devices arecoupled to the traffic control device by the same communication wire,the traffic control device simultaneously sends a heating signal to theheater control devices via the communication wire, the heater receivingunit of each heater control device receives the heating signal, theheater controlling unit of each heater control device turns ON thecorresponding heater power supply unit, and the heater of eachflashlight is lit by turning ON the corresponding heater power supplyunit of each heater control device.
 21. The chained flashlight systemaccording to claim 11, wherein the traffic control device sends 1-bitinformation in the lighting signal for a predetermined pulse signalwidth.
 22. The chained flashlight system according to claim 21, whereinthe predetermined pulse signal width is 0.1 to 499.9 milliseconds.